Step-by-step operated partial revolution wrench



y '8, 1952 P. w. MEYER arm. 2,602,361

' STEP-BY-STEP OPERATED, PARTIAL REVOLUTION WRENCH Filed June 3 1949 3 Sheets-Sheet l t IN'VENTOR.

*--- PETER w. MEYER MlCHHEL RRIOLQ AGE/v6 July 8, 1952 P. w. MEYER ETAL STEP-BY-STEP OPERATED, PARTIAL REVOLUTION WRENCH Filed June 0, 1949 3 Sheets-Sheet 2 m mw l INVENTOR. PETER W. MEYER MICHHEL R. RIOLQ July 8, 19 2 P; w. MEYER EI'AL 2,602,361

STEP-BY-STEP OPERATED, PARTIAL REVOLUTION WRENCH 3 Sheets-Sheet 15 Filed June 0, 1949 INVENTOR. PETER w. MEYER MIOHHEL R.R IOLFI successive operations without need of .justment ,-by, the operator;

Patented July 8, 1952 UNITED STATES PATENT OFFICE.

- Peter W.Meyer, Noroton Heights, and Michael R. Riola,;Bridgeport, .Conn., assignors to Deering {Millikenlteeearch Trust, Greenwich, Conn., a

nonprofittrust of Maine Application June 30, 1949, Serial No. 102,308

The present invention relates to wrenches having predefined stroke and, more particularly, to wrenches adapted for rotating fiyer hub assembliesj 'When rayon or silk single yarns require twisting without doubling, they are passed through an up-tw'iste'r. The bobbin of littwisted yarnis placed upon a vertical spindle, and the yarn is twisted as it passesthrough'two eye wires projecting from a rotatable fiyer. The twisted yarn isthereafter'wound upon a horisontal bobbin.

In normal usage theprojecting eye wires of these flyers become bent or broken, "and the flyers are therefore soconstructed that the wires are replaceable. Ina widely used standard construction, the wires are fitted snugly in guides and their innerends are bent' around ai'otatable' hub: and are locked in place beneath a locking discwhich is. afiixed to the-hub. The locking disc has two flanges which are 'separated by arcs of- 110 and each of which spans an arc of 70. Thus, :by rotating the flanged locking disc through 90, the wire endslare 'released, while a further rotation throughi90- in either direction locks theminto position again.

In the past this disc rotating operation has been ,perfo'rmed with a manually operated wrench, using :a fixture to hold the flyer unmovable. This operation has been troublesome and time-consuming, because the flyers are quite small (us,ua1lynot exceeding 1% inches in length and inch inwidth), thus making r'otatiori'of ,the flanged disc into locking' 'and releasing-posttion a delicate-task, and because the rotatable disc ls hard to turn, as it must'fit tightly in order to prevent loosening ofthewires during-use.

; It is an object of theziprese'nt invention to provide an apparatus for .producingrotational motion through a predetermined. are of rotation. It is ;a further object of the invention to provides wrench of predefinedstroke for releasing and then looking fiyer wires iin place 'iht'wo v special'ad- These and other oblects'and advantages of thisinvefition will be apparentto those skilled in the artfrom the following description, taken in conjunction withthe accompanying drawings, wherein: W i

Fig.1 is a diagrammaticside elevation of an apparatus in accordance with the invention";

Fig. 2 is a partial top plan View on an enlarged scale of thegapparatus' of Fig; 1. a

, 3 shows the electrical circuit of the auraratusiof Fig. 1; a

, 15 Claims. (01. 81- 53) a flyer, and

with three rings Air-pressure lines 24' and 25 ruh tothe Fig. 4 is a detail view on an enlarged scale of the cylinder and wrench vassemlolyo f Fig., 1;

Figs. 5 and '6 aredetails on an enlarged scale of the foot pedal assembly of Fig. 1;

Figs. '7, 8 and 9 are-detail views on an'enlarged scale of a flyer in position on the holding fixture of. the apparatus of Fig. 1, showing different stages of rotation of the locking'idiscduring operation of the. apparatus.

.Broadlyspeaking, the apparatus of the present invention comprises a reciprocating member, the axial motion of which serves to 'operatea rotary member associated therewith, and including means for regulating, the length of the are, of rotation of the "rotary member. ularly; a reciprocating member is provided for moving: a wrench into and out, of en a ement with a locking disc of a flyer positioned upon a fixture and the wrench is caused to rotate through an --arc of rotation determined by the axial stroke of the reciprocating member, at

the fiy The following description applies to the apparatus shown in Figs. 1 00 6 inclusive.

Reference character I indicates a base having a support 2 and a platform 3 fixedly mounted thereon.- Integrally constructed with theplatform 3 is a fixture-or anvil eadapted to receive W V v U having acentral recess 6 in which the hub of the flyerfits. At the upper portion of support 2 there is mounted a p'latfo-rni 1 having a port 8 therethrough, in which port is mounted the reciprocable piston rod 9 of a pneumatic cylinder I0 oi conventional type. The pneumatic cylinder is likewise fixedly fastened to the support 2. The piston I2, w-hichi sequip ped i3, i4 and I5, is affixed to the pisto "rods and is reciprocated within ,the chamher by air pressure which is regulated by the four-wayyalve 16 of conventional design,- such asType'88i M1 (Foot), manufactured by, the

The Valve l6 comprises fourspring-mountd plungers l1, I8, 19 and '20 whose position is controlled by the stop 22. The stop-lsintegraLWit-h the. pedal. 23 and isreCipr cated or pivoted by tiiemovement thereof, suitable .detentmeans being provided to maintainthe pedal in either of two positions, raised or lowered, as is'jgenerally shown in Figure 5. Four lines liilji'i 'intdithe'valve. iiiqiir chamber 25 and lower chamber Z'I respEc veiy,

ofthe cylinder 10, while une 28 is forexhaust of air. andilin'e "29 runs to the source of compressed More pgartioand depends from the recess. 'of the shaft 32 is aflixed a bronze bushing 38,

air. When the pedal 23 is in the raised solidline position shown in Fig. 5 the stop 22 is in the solid-line position shown in Fig. 6 and plungers l1 and 13 are held open while plungers i9 and 20 are urged by their respective springs to a closed position. Thus, air pressure line 24 is connected to air exhaust line 28, plunger ll being open, while line 25 is connected to the compressed air line 29 through open plunger 18. Compressed air, while the valve is in this position, is delivered through lines 25 and 29 to the lower chamber 27 of the cylinder I9, while air is exhausted from the upper chamber 26 of the cylinder l9 through lines 24 and 28. The piston rod 9 is thus raised.

On the other hand, when the pedal 23 is in the depressed dotted-line position shown in Fig. 5, stop 22 is moved to the dotted-line position shown in Fig. 6 and plungers I? and I8 return to a closed position under the urging of their respective springs. Thus, when the pedal is in the depressed position, line 24 i connected to the compressed air line 29 and line 25 to the exhaust 28. Thus, compressed air is delivered through lines 24' and 29 to the upper chamber 26 of the cylinder, while air is exhausted from the lower chamber 21 of the cylinder through lines 25 and 28. The piston rod 9 is thus lowered.

The piston rod 9 has at its lower portion (best shown in Fig. 4) a recess 30 in which is immovably affixed (by the pin 3!) a shaft 32 with a thread having a helical angle beyond the coefiicient of friction. The pin 3i pierces the shaft and both walls of the piston rod, holding the shaft against rotation. The ends of the pin are flush with the outer surface of the piston rod. The pin is removable for removal and repair of the shaft 32 and Other parts associated therewith. The recess '30 and the shaft 32 are in axial alignment with the central recess 6 of the fixture 5.

Spring mounted (by the spring 33) upon the end of shaft 32 is a sleeve 34, to whose upper end is affixed the spiral nut 36. The sleeve 34 screws into the recess 39 over the shaft 32 by means of the spiral nut 36, and is partly screwed over the shaft At the lower end which facilitates rotation of the sleeve about the shaft and also acts as a stop to prevent the spiral nut 36 from unscrewing completely, thus detaching the sleeve from the shaft.

7 At the bottommost portion of the sleeve 34 there is located a wrench 49 having two cleats 42-and 42', spaced apart by an arc of 189, in a recessed portion 43 at the bottom of the wrench.

These cleats engage the flanges 16 and 16' of a 'flyer'locking'disc 12 (see Figs. 7, 8 and 9). The

wrench 'may also have only one cleat, if desired. In this event, the wrench engages one flange of the locking disc. A post 44 disposed in the recess engages the center hole of a flyer upon the anvil '5 and enters the central recess ii of the anvil. Thus it aligns the wrench on the flyer for positive engagement with the flange thereof. The wrench is immovably affixed to the end of sleeve 34 by the pin 45. This pin is similar to pin 31, since both its ends pierce the sleeve and are flush with the outer walls thereof, and it is removable for easy removal or replacement of the wrench. The spring mounting 41 rests within the sleeve 34 below the bushing 38, and it and the top of the wrench 4i! serve as supports for the ends of the spring 33.

Theapparatus is so constructed that the wrench rotates 90 at one stroke of. the piston r microswitch 53 is closed and 180 at the next succeeding stroke of the piston, this cycle being repeated automatically. To this end the following means (best shown in Figs. 1, 2 and 4) are provided. The electric circuit in which they are associated is shown in Fig. 3.

Exteriorly of the piston rod 9 above the p1atform I is threaded the stop nut 49. This stop is adapted to be screwed up and down the piston rod 9. Ordinarily, this stop nut is so adjusted that, at the time that the wrench 49 makes a rotation of 180, the stop nut is brought against the top of the platform 1, halting further downward movement of the piston rod 9, and thus further rotation of the wrench.

At one side of the piston rod 9, upon the platform I, there is mounted the electric solenoid 50. A slide 5| is reciprocated by the solenoid 59 into and out of the dotted-line position shown in Fig. 2, in which position it engages the stop nut 49 upon downward movement of the piston rod 9, and prevents further downward movement of the same thereafter. The slide 5| is made of such a thickness that at the time the stop nut 49 on the piston rod, during a downward stroke thereof, engages it, the wrench has made a rotation. Thereafter, further rotation of the wrench is prevented.

The solenoid is operated electrically by the following means: A spring-mounted microswitch 53 is placed upon the base 54, upon which the foot pedal 23 is mounted. This switch is normally in the open or off position, but is closed (on) upon contact of the angular bar 55 therewith when the foot pedal 23 is depressed, and opens automatically when the foot pedal is raised.

Positioned upon the outside of the cylinder l0 and afiixed thereto is a spring-loaded dimmer switch 56. This switch is flipped successively to the closed (on) and then to the open (off) position (shown in Fig. 3) upon each engagement of the shaft 51 therewith. The shaft 51 is aflixed to one end of the triangular plate 58, the other end of which is fixedly mounted upon the piston rod 9. Thus, the plate 58 and the shaft 5'! re ciprocate with the piston rod 9, and the switch 56 is flipped first .to the on position on one stroke of the piston rod, and then flipped to the of? position on the next stroke of the piston r0 The dimmer switch, microswitch and solenoid are connected together in series in the electric circuit, shown in Fig. 3, to a standard volt alternating current line. When the dimmer switch 56 is closed (in the on position) and the (in the on position) the solenoid 50 is actuated. When, however, the dimmer switch 56 is in the off position, then the circuit is open, even though the microswitch 53 is in the on position, and the solenoid 50 is not actuated. Since the dimmer switch is flipped to the on and then to the off position on successive strokes of the piston by operation of the shaft 51, the solenoid 50 is actuated only on alternate strokes of the piston-rod 9, even though the microswitch 53 is closed each time the pedal 23 s depressed. A light59 on the dimmer switch is illuminated when the circuit is closed, 1. e.,;when both switches 53 and 56 are closed. 7

As has been stated, the position of the stop nut 49 is so adjusted that the ,wrench' 40 makes a maximum rotation of When the solenoid 50 is actuated, and the slide 5| which hasa p re determined thickness contacts and halts downward movement of the piston rod, the wrench 40 rotates only 90. Thus, the wrench alternately is cessive strokes oithe pistcn' rod; because the solenoid' 'fifl is actuated-only" on alternate strokes thereof. a I

Two =rods,'-only one. or which is shown- (at: 60) pass-through the-plateiii forreciprocation there in. v A stop-nut I (61 -on:rod 60')- -prevents therods from falling-through the plate. Each rod. is enveloped by a compressionspring ;('62 on rod 60) and the-springsare compressed between the lower sur-tace of the- :plate 58 andtheupper: surface: "of the :rubber surfaced pads: (63 on rod 60) respectively, which are iafiixedl to. the lowerlends of the rods. 'The rods are normally: held in the position shown, but are 'so 'positioned'onz-the plate 582that the -pads engage'v the wires. ot a flyer mounted upon the anvil-iupon a lowering. of theipiston rod S -before .the wrench .i lfizaengages the: flange thereof, 'and hold-the flyer firmly place. for action thereon by. theiwrench.

Operation? of: the? apparatus: isextremely. simple; and can bex carriedout by relatively unskilled operators. The'steps of operation are. illustrated in Figs. 7, 8 =9 and. reference is now; made to these figures l in a conjunction with Figs. 1-6, inelusive.

.i-Duringbthis stroke! of -.the.piston'-ro'd 9,.: the dimmer switch 56' is iii-the. .on position; Thus, whenztheroperator depresses. the pedal 23 and the microswitch; 53 is v closed; the. :circuit: closed, light 59 is i1luminated, the: solenoid: 53' is. actu ated, and the slide-51. engages the 'stop' nut=49 and; prevents iurther I downward movement of the piston rod 'after contact: therewith, thus: halting rotation 'of-'-.the wrench-1 it-after it "has: rotated througman arc of 90.

"As flyer 10; the locking. disc' 12 ofwhich is .int the positionshown 7 :placed in the fixture 5. The operator depresses the pedal- 23', thus closing the switch:5.3,:5and the. electric circuit,. so *that slide 51: engagesthepiston rod 9, and'adniitting air under pressure to the upper chamber 26* of the cylinder Illthrough the lines; 24 and 29. .-Simultaneously; air is released from the-lower chamben 21 of the cylinder'throughthe lines Hand 28, and: therebyunder the'. influence of the increased airi-pressurevabove the piston I2, apdownward stroke. of therpistontrod 9 caused to. occur. Thusythe spring-mounted pads ,(onlylpad 63 is shown) yare brought into engagement with the flyer' wires lt, "and 15,holding the flyer steady while-the. central guide-post 44 guides. thewrench 40=-into1precisa engagement with the fiyer locking di'scz12.;j

As the piston rod 9 continues its 'do'wnward strokeypressure isuexerted-upon the wrench 40, causing the-sleeve 34' torotate with the spiral nut 365-upwardly over the shaft 32, and turningwthe wrench 40 tot-he right. The cleats 42 and 42? of thBQWIGIlChlO thusengage -the flanges l6 and 16 and rotatethe fiyer locking disc l2;v As thesleeve and wrench-rotate; the spring 33 is compressed. A-iter the wrench; has rotated 90?,v the stop :i nut da engages the slide 5-l,-halting further downward'rmovement of- -the piston rod; and rotation of thewrench. 1 1 wThe: operator' therr raises the pedal 23, thus open-ing'the .-microsw-iteh53,v and shifting thevalve stop'2'2- to the -selid-line position shown in Fig.6. By this. 1novement ofthe valve stop, line. 25 is connected. tothe; compressed air line 2-9 while line 214.3 connected with-the. exhaustline 18-; thus, under the rose oflltheQincreased airpressure in the lower chambefz'l'ofthe cjr'lindenupom the bottom of theifpistoh .l 2 combined. with exhaust or air-rrom'tneupperchan ber zathepiston rod 6 9 is-raised to-its initial -position. :Atthesame time, underthe-io-rce of the compressedspring 33, the sleeve 34 is causedtounscrewitself from the shaft 32 by-means of the-spiral nut. 36, returning the wrench-to -its original positiontandthe springmounted pads (only pad: 63-is-shown) are also returned to w their: original position. 5 When the piston rod 9 reaches its uppermostiposition, the shaft 51 "flips the dimmer switch SB- to the off position, thus preparing the electric circuitifor the'next stroke',-and-making it impossible toactuate the solenoid 50*when the: microswitch 53 is closed-the-next time the pedali23 is depressed. Atthispoirit-the flanges lli and 13- of the flyer lock-ingdisc' 12' are in the position shown. in Fig.8. The operator-maynow easily remove the original wires 13, 14 and 15 andhinsert newiwires.

The operator now causes the. =pistonrod 9 to make'a second downward stroke by; depressing the pedal 23, which 'returns the valvetstopt. 22 to the dotte'd -l-ine positionshownin Fig. 6 and resultsin application of air pressure to'the upper surface of the piston l 2=in the upper. portion. H of thecylinder' chamber as set forth sabove." This again bringsthe spring-mounted pads and the wrench 40 into engagement with theflyer'. On this-stroke, however, even though switch 53 is on, the electric circuit is open, because the .dimmer switch 56 in the oif position, so that the solenoid: cannot be actuated,=and theispiston rod 9 makes a full stroke, rotating the'wrench-M through-its maximum arc of. 180 Icy-the time stopanutr 49 contacts the plate I. 7

When the wrenchidli firstengages the locking disc 12, the cleats142 and-42-'are,inthe position shown inFig. 8. "Afterthe-wrench' 40 has rotated through its-firstQO" arc,-= the.;cleats;42 and 42 are in the position shown in Fig. 9, and atthis point first engage'thelflanges wand [6, respectively. As the wrench: 40:, rotates throu h ,its second 90? are with the cleats inengagementwith flanges, it returns the disc 12 to a position similar to thatshown: iniFig.. '7,- except thatthe-two flanges 1B and 'lfi'areznow reversed ingposition. Thenew wires. are .thuszlocked, in -place.

:The operator nowelevates the pedal 23,;which opens. the microswitch 5.3; .and i returns; the valve stop 22 to the solid-lineposition shown inqFig. 6. This-againw-causes thepiston rod 9'to rise, returning. the spring-mountedpads and the wrench to their original position. At the same time, the shaft 51 engages,andflipsthedimmer switch 56 tothe .fon positiomthus, preparing the electric circuit for the nextjstroke of the piston, so that whenthe microswitch 53 is closed-upon the-next depression of the'pedal 23; solenoid 5.0 and slide 51 are actuated, once. again limiting the stroke of the piston rod and the rotation of thewrench 4n toran .arc of'90- -iThe-flyer 10 is then removed from the fixture 5 and the apparatus is ready to repeat the cycle of operations on another flyer.

The particular embodiment of the invention illustrated has amechanicjal lift Bllcomprising an ejector pin 8!, and -a;,hand= control 82 afiixed to a lever: 83'. :Thepin -8;|- .reciprocatesin avertically aligned-orifice't l inbase Landplatform 3,-

connecting' directly to the recess 6 in the anvil 5. The-lever is pivoted on the rod 85, which is supported uponthe plate 86 depending from base I.

Thus-the pin- BI is raised" or lowered through orifice-Baby operation of the hand control 82.

' The pin 8| engages a flyer hub from beneath and not'an essential part of the apparatus of the invention.

' It will also be apparent that it is not necessary thata pneumatic cylinder be used for operation of the device, as an electric motor or other source of power may be employed. Various additional changes may be made in the particular constructions illustrated without departing from the pirit of the invention.

From the foregoing description, it will be apparent that the wrench of the invention is simple of construction, requires a minimum of adjustment and is relatively compact. It permits rapid and eas replacement of fiyer wires in standard or custom-made flyer hubs, the wrench itself being easily removable upon removal of a pin so that a wrench with cleats arranged to fit any desired type and size of hub flange may be in-, serted.

The following is claimed:

1. In a device: for rotating a part of a work piece of the type having a member mounted for reciprocatory movement toward and from a work piece, a wrench keyed to said member and adapted to be brought into engagement with a part of a work piece during movement of said member toward the work piece, and to rotate relative to the member while in engagement with said part upon further movement of said member toward the work piece, the improvement comprising stop means mounted adjacent the reciprocatory member and movable from a position out of engagement with said reciprocatory member toa position engaging said reciprocatory member and means actuated electrically only on alternate strokes'of said member toward the work piece to move said stop means into engagement with'said reciprocatory member in order to limit the extent of reciprocation thereof and thus to limit the extent of rotation of said wrench.

2. A device according to claim 1 in which said wrench and said reciprocatory member are formed with cooperating parts permitting said Wrench to rotate in one direction from it original position, relative to said member, to another predetermined position, relative to said member, while in engagement with said part upon movement of said member toward the Work piece, and then to rotate in the reverse direction relative to said member upon movement of said member away from the work piece until it has returned to said original position.

3. The device according to claim 1 including means for'electricall actuating saidstop means comprising, connected in series in an electric the work piece, and to be thrown open upon each strokeof said reciprocatory member away from the work piece. l T

l. The device according to claim 3 including meansadapted to reciprocate with said reciprocatory mcmber'to operate said first switch upon completion of each full reciprocation thereof.

5. The device according to claim 3 including means responsive to the control of an operator for throwing said second switch closed upon each stroke of said reciprocatory member toward the work piece, and then to throw said switch open upon the next succeeding stroke of said reciprocatory member away from the work piece.

6. In a device of, the type including a vertically disposed non-rotatable shaft mounted for longitudinal reciprocatory movement toward and from a work piece, a cylinder rotatively mounted upon said shaft, a wrench keyed to said cylinder so as to rotate therewith upon engagement with a part of said workpiece during downward movement of the shaft, the improvement which comprises a detent mounted adjacent said shaft and movable from a position out of engagement with said shaft to a position engaging said shaft and electrically actuated means responsive to the movement of said shaft, to move said detent into engagement with said shaft on alternate strokes, limiting the downstroke of said shaft to control the angle of rotation of the wrench.

7. The deviceaccording to claim 6 wherein said stop means comprises a member adaptedto engage said reciprocatory shaft, a solenoid adapted to thrust said member into and out of engage ment with said reciprocatory shaft, connected in series with an electric switch adapted to be thrown open upon one full reciprocation of said shaft; and then to be thrown closed upon the next succeeding full reciprocation of said shaft, and a second electric switch adapted to be thrown closed prior to each downward stroke of said reciprocatory shaft and to be thrown open prior to each upward stroke of said reciprocatory shaft.

8. The device according to claim 7 including means associated with said reciprocatory shaft for automatically actuating said first switch upon completion of each full reciprocation of said shaft.

9. A device according to claim 7 including means responsive to the control of an operator to actuate said second switch upon completion of each stroke of said reciprocatory shaft, whereby said stop mean engages said reciprocatory shaft on alternate downward strokes thereof so as to limit rotation of said wrench, whereby when the work piece is a flyer having a flanged flyer wire locking hub, reciprocation of the shaft causes the wrenchv part: to engage the flange and to rotate it on the first stroke into wire unlocking position and on the second stroke into wire looking position. y

' '10. A device according to claim 9 wherein said wrench part is so positionedas to rotatably engage a flange of a flyer hub on one downstroke immediately after said wrench begins to rotate and on the other downstroke after said wrench has rotated through an arc of 90, and said first and second switches are thrown closed on said first-mentioned downstroke of said switch so as to limit rotation of said wrench to 90, and said first switch is thrown open on said last-mentioned second downstroke of the shaft so as to allow rotation of said wrench to a full 180", whereby the wrench part engages androtates a flyer hub flange through an arc of 90 into wire unlocking position on the first stroke, and on the second stroke rotates through the first 90'arc, then engages the flange and rotatesit "through a further arc of 90 intowire locking position.

111: Ina device. for rotating a part of a' work piece of. the type having a wrench mounted on the free end of a sleeve dependent from a spiral nut, which nut rides on a spiral shaftmounted for reciprocatory movement toward and away from the work piece, saidwrench being adapted tobe brought into engagement with the part of the work piece to be rotated, the combination comprising means adapted when actuated to limit the angle of rotation of the part of the work piece by the wrench by limiting the extent of movement of the shaft member toward the work piece and electrical means for actuating said limiting means.

12. The device according to claim 11 wherein said last mentioned means comprises a solenoid adapted when energized to actuate said limiting means, a normally open energizing circuit for said solenoid and means for closing said circuit only on alternate strokes of said member toward the work piece.

13. The device according to claim 12 wherein said circuit closing means comprise a pair of series connected switches, means movable with said member for reversing the condition of one of said switches on each stroke of said member toward the work piece and means for maintaining the other of said switches closed during each stroke of said member toward the work piece and for maintaining such latter switch open during movement of said member away from the work piece.

14. The device according to claim 13 including power means for moving said member toward the work piece and operator controlled means for coupling said power means to said member, said last mentioned switch being mechanically connected to said operator controlled means for closure thereby.

15. In a device of the type including a vertically disposed spiral shaft mounted for longitudinal reciprocatory movement toward and from a work piece, a spiral nut riding on said shaft, a sleeve dependent from said nut and rotatable therewith, and a wrench carried by the free end of said sleeve so as to rotate upon engagement with a part of the work piece during downward movement of the shaft, the improvement which comprises electrically actuated stop means limiting the downward stroke of said shaft to control the angle of rotation of the wrench whereby when the work piece is a fiyer having a flanged fiyer wire locking hub and said wrench is moved downward to engage the hub flange and rotate the hub, rotation thereon is stopped when the fiyer wires are unlocked.

PETER W. MEYER. MICHAEL R. RIOLA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,261,432 Parslow Apr. 2, 1918 1,322,612 Proske et al Nov. 25-, 1919 1,742,040 Lynch et a1. Dec. 31, 1929 1,887,216 Reynolds Nov. 8, 1932 7 2,119,968 Shoff June '7, 1938 2,143,173 Shofi Jan. 10, 1939 2,3004392 Austin Nov. 3, 1942 2,300,435 Ricciardi Nov. 3, 194 2,433,959 Runkle Jan. 6, 1948 

